Answer:
1. $20,000 cost already incurred to a produce. - Irrelevant
This cost has already been incurred in the initial production and as such are classified as sunk costs. Sunk costs are not relevant to the decision on whether to sell or process the product further.
b. $12,000 selling price - Relevant
As this amount relates to the selling price were the product not to be processed further, it is relevant to the sell or process the products further decision.
c. $16,000 additional processing costs - Relevant
This is the incremental cost should the product be processed further and so is relevant to the decision.
d. $30,000 revenues from processing further. - Relevant.
As the total revenue that could be realized if the product is processed further, this is very relevant to the decision on whether to process further or sell.